# elm > Compile and run Elm source files. > More information: . - Initialize an Elm project, generates an elm.json file: `elm init` - Start interactive Elm shell: `elm repl` - Compile an Elm file, output the result to an `index.html` file: `elm make {{source}}` - Compile an Elm file, output the result to a JavaScript file: `elm make {{source}} --output={{destination}}.js` - Start local web server that compiles Elm files on page load: `elm reactor` - Install Elm package from : `elm install {{author}}/{{package}}`